WPR17FA146

A partial loss of engine power for reasons that could not be determined during postaccident examination in combination with the low cruise altitude selected by the pilots, which resulted in an ocean ditching. The lack of personal flotation devices likely contributed to the drowning of one of the pilots.

The two pilots, who were both qualified to fly the experimental light sport airplane, were conducting a local flight with two other similar airplanes from the same flight club. After takeoff, the three airplanes proceeded to the ocean shoreline and then flew slightly offshore along the coast. The flight was conducted at a low altitude, which, once over the ocean, was about 300 ft. Soon after reaching the ocean, both pilots noted a "skip" in the engine. They decided to climb for safety and turn around to return to their departure airport. Despite moving their respective throttles to the full throttle position, neither pilot was able to obtain full power from the engine to effect a climb, and the engine rpm began slowly decreasing. Because the airplane was no longer able to maintain altitude, control of the airplane was transferred to the pilot who held a flight instructor certificate. Due to the rocky coastline and traffic on the road along that coastline, the pilots determined that they would have to ditch in the ocean. After the ditching, both pilots escaped from the airplane, and, when the airplane began to sink, they began to swim to shore, which was about 200 ft away. Neither pilot appeared injured. No personal flotation devices were aboard the airplane or worn by the pilots. One pilot successfully swam to shore, but the other pilot drowned. The airplane washed ashore the following morning and was heavily damaged by wave action, contact with rocks, and the salt water immersion. Postaccident examination did not reveal evidence of any preaccident mechanical failures but obscuration or destruction of such evidence due to the ditching and subsequent environmental damage could not be ruled out. The examination revealed several maintenance-related discrepancies. The type of fuel line clamps used and the installation of the fuel pumps were not in accordance with the engine manufacturer's specifications, and this could have affected fuel delivery to the carburetors. After the accident, the throttle cable was found disconnected from the cockpit control, and it could not be determined whether that was a result of a partial slippage during flight, which would have limited or eliminated pilot control of the engine rpm and power. Although a similar airplane in the flight did not report any carburetor icing, the symptoms described by the surviving pilot were consistent with carburetor icing, and the ambient temperature and dew point values allowed for the possibility of carburetor icing. Despite such equipment being recommended by the engine manufacturer, the lack of carburetor heat provisions on the accident airplane prevented the pilots from being able to prevent carburetor icing, or counter carburetor icing if it did occur. Finally, although the engine manufacturer specified an overhaul interval of 300 hours, the flight club elected to adhere to a 450-hour overhaul interval advocated by a repair facility that was not approved by the engine manufacturer. At the time of the accident, the engine was about 127 hours beyond the manufacturer-recommended 300-hour overhaul interval. Although none of these discrepancies discovered during the investigation was able to be definitively linked to the accident, all were potential factors, and all were maintenance-related. The low glide ratio of the airplane (about 5:1) limited its range in the event of a loss of engine power, reducing the forced landing site options available to the pilots. The forced landing site options were further reduced by the pilots' decision to operate at 300 ft, a very low altitude. The pilots' over-water route and low cruise altitude were reported to be common for pilots in the flight club. Even though the altitude and route combination increased the likelihood of an ocean ditching in the event of a loss of engine power, neither the pilots nor the airplane were equipped for an ocean ditching. Precautions such as higher over-water cruise altitudes and water-ditching equipment, such as personal flotation devices, may have prevented this event from becoming a fatal accident.

HISTORY OF FLIGHT On July 8, 2017, about 1647 Pacific daylight time, a Quicksilver MXL-II Sport experimental light sport airplane, N2812, sustained unknown damage when it ditched in the Pacific Ocean near Point Mugu, California. The two pilots on board escaped from the airplane before it sank. One pilot successfully swam to shore, but the other pilot died during his attempted swim to shore. The airplane was owned by Sky Knights Flight Club (SKFC) and was operated by the pilots under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight that departed from Camarillo Airport (CMA), Camarillo, California, about 1630. According to the surviving pilot, he and the other pilot were both members of SKFC, which was based at CMA. Each of the pilots was qualified by the club to operate the airplane on his own. The club also owned two other experimental light sport airplanes similar to the accident airplane. These were a Quicksilver Sport IIS airplane, N1712, and a Quicksilver MXL Sport single-place airplane, N7712. On the day of the accident, a total of five persons, including the two accident pilots, planned to fly the three airplanes in loose formation south to the shoreline and then proceed southeast from there for a local flight. The accident airplane was equipped with side-by-side seats and dual controls. According to the surviving sport pilot, he took the left seat and the other pilot, who was a private pilot and a certificated flight instructor (CFI) for light sport aircraft, took the right seat, but this was not an instructional flight. They departed CMA via the "southeast pattern," which was one of three pre-specified routes to exit the CMA traffic area. They departed with about 10 gallons of fuel on board, and the sport pilot was the pilot flying. He estimated that it took about 15 minutes to reach the shoreline, which was about 7 miles south of CMA. At the shoreline, the three airplanes turned left, which put the shoreline off their left sides. Shortly after they passed a large rock outcrop known locally as "Mugu Rock," the sport pilot felt a "skip" in the engine. At that time, they were cruising off the shoreline and above the ocean at an altitude of about 300 ft. The skip repeated a few times, and the sport pilot then asked the private pilot whether he felt it too; the private pilot replied in the affirmative. They decided to reverse course and return to CMA and also advised the other two airplanes of their situation and intentions. They reversed course, the engine irregularity continued, and the two agreed that they should climb to gain altitude in case the situation deteriorated. At that time, the sport pilot advanced the throttle to climb, but the rpm only went to about 5,900, instead of the desired target value of 6,200 to 6,300 rpm. The sport pilot asked the private pilot to advance his throttle to increase the rpm. The private pilot pushed on his throttle but was unable to increase the rpm above 5,900. The rpm then slowly decreased. The airplane could not climb and then became unable to maintain altitude. Due to their different experience levels, the two pilots agreed that the private pilot should now become the flying pilot, and a transfer of control was effected. The rpm continued to decrease slowly over a period of 4 to 5 minutes, and it became apparent to the pilots that they would have to conduct a forced landing. Due to the rocky coast, hilly terrain, and crowded highway that paralleled the shoreline, the pilots realized that they would have to either continue flight to reach a sandy beach or ditch the airplane in the water. The continued decrease in rpm combined with the lack of a suitable landing location forced the pilots to ditch the airplane just offshore. The airplane touched down slowly and under control, and it initially remained afloat. The two occupants both successfully escaped from the airplane and stayed with it until it began to sink. They then began swimming to shore, which was about 200 ft away. The sport pilot was ahead of the private pilot, and they maintained verbal contact as they made their way to shore. The sport pilot kept verbally checking on the private pilot; initially the private pilot said he was fine, but later during the swim, the private pilot said that he was "getting tired." The sport pilot reached the shore, climbed out onto a rock, and then turned to see that the private pilot was face down in the water and was not moving. A bystander swam to the private pilot and pulled him to shore, where he and the pilot then pulled the private pilot from the water. The sport pilot and the bystander attempted to resuscitate the private pilot, as did the paramedics who arrived shortly thereafter. At least one of the other two airplanes in the formation orbited the ditching site for a short time, and both of those airplanes returned safely and uneventfully to CMA. Photographs indicated that the accident airplane appeared to remain intact after it ditched and then submerged in the water. The morning after the accident, the airplane was found washed ashore. The airplane incurred substantial damage as a result of exposure to the rocky coast and wave action. The airplane was recovered later that morning and transported to CMA for examination by NTSB and FAA personnel. PERSONNEL INFORMATION Sport Pilot (Left Seat) Federal Aviation Administration (FAA) records indicated that the person seated in the left seat held a sport pilot certificate with an airplane single-engine land rating that was issued in May 2012. He did not hold an FAA medical certificate, nor was he required to hold one to exercise the privileges of his sport pilot certificate. Despite several requests of the pilot, the National Transportation Safety Board (NTSB) investigator-in-charge was unable to obtain information regarding the pilot's flight experience. Private Pilot (Right Seat) FAA records indicated that the person seated in the right seat held a private pilot certificate with an airplane single-engine land rating and a flight instructor certificate with a sport rating. His most recent FAA third-class medical certificate, which was issued in April 2008, had expired; he was not required to hold a medical certificate to fly as a sport pilot. Copies of some of the most recent pages of the private pilot's flight logbook were provided to the investigation. The most recent entry in the flight logbook was dated April 1, 2017. As of that date, the private pilot had logged about 377 total hours of flight experience, including about 64 hours in light sport aircraft. The logbook also indicated that he had logged about 34 hours as a flight instructor. The private pilot's most recent flight review was completed in September 2016. SKFC Mechanic One individual at SKFC was primarily responsible for the maintenance and inspection activities on the three SKFC airplanes. He reported that he had been a full-time member of SKFC for about 3 to 4 years and that he was not compensated by SKFC for his services as the SKFC mechanic. He held a private pilot certificate, an aircraft mechanic certificate with airframe and powerplant ratings, and a light sport aircraft repairman certificate. In the spring of 2017, he successfully completed two Rotax-approved training courses, one for two-stroke engines and one for four-stroke engines. AIRCRAFT INFORMATION The airplane was a high-wing ultralight-like design with conventional flight controls. The structure consisted of an uncovered aluminum and steel tube framework with two side-by-side seats and a tricycle-configuration wheel landing gear. It was powered by a Rotax 582 model 99-series engine that was mounted atop the airframe in a pusher configuration. The airplane was not equipped with any type of whole-airplane emergency parachute. FAA records contained conflicting information